1. Field of the Invention
The present invention generally relates to a compound semiconductor device and a method for controlling characteristics of the same, and more particularly, the present invention relates to a compound semiconductor device and a method for controlling characteristics of the same to obtain a homogeneous threshold voltage among plural transistors or a homogeneous resistivity among plural resistors.
This application is a counterpart of Japanese application Serial Number 073396/1997, filed Mar. 26, 1997, the subject matter of with is incorporated herein by reference.
2. Description of the Related Art
A conventional electronic component includes a plurality of field effect transistors and a plurality of resistors. The plurality of field effect transistors respectively have gates of different widths. Improved controllability of threshold voltages of the field effect transistors is important in stabilizing the performance of the electronic component.
The conventional method for controlling a threshold voltage of the field effect transistor is as follows:
First and second field effect transistors are simultaneously formed on the semiconductor chip. The second field effect transistor serves as a monitor for observing the process steps. That is, the threshold voltage of the second field effect transistor is measured after the ion-implantation for establishing a desired threshold voltage is completed When the measured threshold voltage is lower than the desired value, the ion-implantation for establishing the desired threshold voltage is carried out for the second time.